CN108263383B

CN108263383B - Apparatus and method for controlling speed in a coordinated adaptive cruise control system

Info

Publication number: CN108263383B
Application number: CN201711299022.2A
Authority: CN
Inventors: 金润洙; 许明善; 鲁东奎; 吴荣哲; 郑仁溶; 成修莲; 权亨根; 黄大成; 申基喆; 朴钟录; 柳初珑; 黄俊植; 李民秉; 朴胜煜; 卢鹤烈; 俞炳墉
Original assignee: Hyundai Motor Co; Kia Motors Corp
Current assignee: Hyundai Motor Co; Kia Corp
Priority date: 2016-12-30
Filing date: 2017-12-08
Publication date: 2022-12-06
Anticipated expiration: 2037-12-08
Also published as: EP3342669A1; KR20180078978A; CN108263383A; KR102107726B1

Abstract

An apparatus and method for controlling a vehicle speed based on information about a preceding vehicle traveling in the same lane, which can be acquired using vehicle-to-anything (V2X) communication, in a Coordinated Adaptive Cruise Control (CACC) system. The CACC system includes: a communication unit that receives vehicle information from a nearby vehicle using V2V communication; an information collection unit that collects vehicle information of a nearby vehicle and a target vehicle using a sensor; and a control unit that determines a preceding vehicle and a more preceding vehicle using the sensor, selects first and second target vehicles to be followed by the host vehicle based on vehicle information of the preceding vehicle and the more preceding vehicle and vehicle information of the nearby vehicle, and controls a traveling speed of the host vehicle based on speed information of the first and second target vehicles.

Description

Apparatus and method for controlling speed in a coordinated adaptive cruise control system

Technical Field

Exemplary embodiments of the present disclosure relate to an apparatus and method for controlling speed in a coordinated adaptive cruise control (hereinafter, referred to as "CACC") system, and more particularly, to an apparatus and method for controlling vehicle speed based on information about a plurality of preceding vehicles traveling on the same lane acquired using V2X (vehicle-to-anything) communication.

Background

An adaptive cruise control (hereinafter referred to as "ACC") system is a system that operates to perform autonomous driving at a speed equal to or lower than a speed set by a driver and maintain an inter-vehicle distance from a target vehicle at a predetermined distance or more. The ACC system provides a function for maintaining a sufficient vehicle distance to prevent a collision with a preceding target vehicle acquired by a distance and/or position measuring sensor mounted on the vehicle, or a cruise function that performs automatic driving at a speed set by a user.

The ACC system may enable a driver to adjust the traveling speed of a vehicle without continuously operating an accelerator pedal in order to provide convenience to the driver, and may achieve safe driving by maintaining a predetermined distance from a target vehicle and preventing the vehicle from traveling beyond a set speed.

On the other hand, the CACC system is a system that can improve ACC functions by adding V2X (vehicle-to-everything) communication to the above ACC system. The CACC system may receive a road speed limit through V2I (vehicle-to-infrastructure), receive information about a target vehicle traveling on the same lane through V2V (vehicle-to-vehicle), and then improve ACC performance based on the received information.

However, since the CACC system in the related art adjusts the speed of the own vehicle based on the speed of the target vehicle after setting a vehicle immediately in front of the own vehicle as the target vehicle, sudden start or sudden acceleration may frequently occur.

Disclosure of Invention

The present disclosure provides a CACC system that determines a travel speed based on travel information of a preceding vehicle and a further preceding vehicle, and a control method thereof.

Other objects and advantages of the present disclosure will be understood by the following description, and become apparent with reference to the embodiments of the present disclosure. Also, it is obvious to those skilled in the art to which the present disclosure pertains that the objects and advantages of the present disclosure can be achieved by the means as claimed and combinations thereof.

According to one aspect of the present disclosure, a coordinated adaptive cruise control (hereinafter, referred to as "CACC") system provided in a host vehicle to control a traveling speed of the host vehicle includes: a communication unit configured to receive vehicle information including a position and travel information from a nearby vehicle using V2V (vehicle-to-vehicle) communication; an information collection unit configured to collect vehicle information of a nearby vehicle and vehicle information of a host vehicle using a sensor provided on the host vehicle; and a control unit configured to determine a preceding vehicle and a further preceding vehicle using a sensor provided on the own vehicle, select a first target vehicle followed by the own vehicle and a second target vehicle followed by the first target vehicle based on vehicle information of the preceding vehicle and the further preceding vehicle and vehicle information of the nearby vehicle acquired by the communication unit, and control a traveling speed of the own vehicle based on speed information of the selected first target vehicle and the second target vehicle.

The CACC system according to the aspect of the present disclosure may further include a driving unit configured to control the throttle and the brake, and/or a Driver Vehicle Interface (DVI) unit configured to notify the driver of a state information system of the CACC, wherein the control unit controls the driving unit to control a traveling speed of the own vehicle.

The control unit may include a state management unit configured to manage a state of the CACC system; a target vehicle selection unit configured to determine a preceding vehicle and a further preceding vehicle using a sensor provided on the own vehicle, and select a first target vehicle followed by the own vehicle and a second target vehicle followed by the first target vehicle based on vehicle information of the preceding vehicle and the further preceding vehicle and vehicle information of the nearby vehicle acquired by the communication unit; and a travel management unit configured to control a travel speed of the own vehicle based on the speed information of the selected first target vehicle and second target vehicle.

The state management unit may display the state of the CACC system as one of the following states: an off state in which the CACC system is not operating; a standby state in which the CACC system operates but does not control the traveling speed of the own vehicle; an ACC active state in which the traveling speed of the own vehicle is controlled using only information acquired from the own vehicle in a state in which there is no vehicle connected by V2V communication in the region of interest; a cooperative activation state in which there are nearby vehicles connected by V2V communication in the region of interest, and the traveling speed of the own vehicle is controlled using information from the nearby vehicles acquired by the V2V communication and information acquired from the own vehicle.

The information collection unit may include a distance sensor configured to sense a front object, wherein the target vehicle selection unit determines presence of a front vehicle and a further front vehicle traveling in the same lane as the own vehicle based on a sensing result of the distance sensor.

The target vehicle selection unit may determine an object having a width equal to or greater than a first predetermined reference width in a driving lane of the own vehicle as the preceding vehicle, according to a sensing result of the distance sensor. The target vehicle selection unit may determine an object having a width equal to or greater than a second reference width acquired by the position of the preceding vehicle in the driving lane of the own vehicle as a more preceding vehicle according to a sensing result of the distance sensor.

The target vehicle selection unit may determine an object having a width equal to or greater than a second reference width during a predetermined reference time as a more preceding vehicle if the curvature of the driving lane of the own vehicle is less than a predetermined reference curvature. The target vehicle selection unit may determine an object whose width increases during the reference time as a more preceding vehicle among objects having a width equal to or greater than the second reference width.

The target vehicle selection unit may acquire the second reference width based on the distance to the preceding object and the position of the preceding vehicle. The target vehicle selection unit may determine an object, which the distance sensor senses the plurality of surfaces and has a width equal to or greater than a second reference width, as a more front vehicle if the curvature of the driving lane is equal to or greater than a predetermined reference curvature. The target vehicle selection unit may determine an object closest to the preceding vehicle as a more preceding vehicle if the distance sensor senses a plurality of objects having a width equal to or greater than the second reference width.

The travel management unit may control the own vehicle to travel in accordance with either one of a first travel speed corresponding to the travel information of the first target vehicle and a second travel speed corresponding to the travel information of the second target vehicle. The travel management unit may control the own vehicle to travel according to one of the first travel speed and the second travel speed having a smaller value.

In a case where the curvature of the traveling lane of the host vehicle is smaller than the predetermined first reference curvature, when the first target vehicle deviates from the traveling lane of the host vehicle, the travel management unit may control the host vehicle to travel at a travel speed determined from the travel information of the first target vehicle and the second target vehicle. The travel management unit may determine whether the first target vehicle deviates from the traveling lane of the host vehicle using the speed and the position of the first target vehicle acquired from the sensing result of the distance sensor.

The distance sensor may comprise a lidar.

The information collecting unit may further include a camera that acquires a front image, wherein the target vehicle selecting unit acquires information of a lane in which the host vehicle travels from the front image acquired by the camera.

According to another aspect of the present disclosure, there is provided a method for controlling speed in a coordinated adaptive cruise control (hereinafter, referred to as "CACC") system provided in a host vehicle to control a traveling speed of the host vehicle, the method including: acquiring, by a communication unit, vehicle information of a nearby vehicle using V2V communication; determining, by a controller, a leading vehicle and a further leading vehicle using a sensor provided on the own vehicle; determining, by the controller, a first target vehicle and a second target vehicle by comparing vehicle information of the own vehicle with vehicle information of a preceding vehicle and a further preceding vehicle; determining, by the controller, a traveling speed of the host vehicle using the traveling information of the first target vehicle and the second target vehicle; and controlling the own vehicle by the controller according to the determined running speed.

The step of determining the preceding vehicle and the further preceding vehicle using the sensor of the own vehicle may include: sensing a front object; determining a preceding vehicle that is traveling in the same lane as a traveling lane of the own vehicle based on the sensing result; and determining a further forward vehicle using the determined position of the forward vehicle.

The step of determining the vehicle in front may comprise: according to the sensing result, an object having a width equal to or greater than a predetermined first reference width in the driving lane of the own vehicle is determined as a preceding vehicle. The step of determining a further forward vehicle may comprise: according to the sensing result, an object having a width equal to or larger than a second reference width, which is acquired by the position of the preceding vehicle, in the driving lane of the own vehicle is determined as the further preceding vehicle.

The step of determining a further forward vehicle may comprise: if the curvature of the traveling lane is less than the predetermined reference curvature, an object having a width equal to or greater than the second reference width during the predetermined reference time is determined as a more preceding vehicle. The step of determining a further forward vehicle may comprise: an object whose width increases during the reference time among objects having a width equal to or greater than the second reference width is determined as a more preceding vehicle.

The step of determining a further forward vehicle may comprise: acquiring a second reference width based on the distance to the preceding object and the position of the preceding vehicle; and determining an object having a width equal to or larger than the acquired second reference width in the driving lane of the own vehicle as a more preceding vehicle. The step of determining a further forward vehicle may comprise: if the curvature of the traveling lane is equal to or greater than a predetermined reference curvature, an object that senses the plurality of surfaces and has a width equal to or greater than a second reference width is determined as a more forward vehicle. Determining a further forward vehicle may comprise: if a plurality of objects having a width equal to or greater than the second reference width are sensed, the object closest to the preceding vehicle is determined to be a more preceding vehicle.

Determining the travel speed of the host vehicle using the travel information of the first target vehicle and the second target vehicle may include: acquiring a first driving speed corresponding to driving information of a first target vehicle; acquiring a second driving speed corresponding to the driving information of a second target vehicle; and determining the traveling speed of the own vehicle from any one of the first traveling speed and the second traveling speed. Determining the travel speed of the host vehicle from any one of the first travel speed and the second travel speed may include: the one of the first running speed and the second running speed having the smaller value is determined as the running speed of the own vehicle.

Determining the travel speed of the host vehicle using the travel information of the first target vehicle and the second target vehicle may include: determining whether the first target vehicle deviates from the traveling lane of the host vehicle if the curvature of the traveling lane of the host vehicle is smaller than a predetermined first reference curvature; and determining the traveling speed of the host vehicle using the traveling information of the first target vehicle and the second target vehicle if it is determined that the first target vehicle deviates from the traveling lane of the host vehicle. Determining whether the first target vehicle deviates from the driving lane of the host vehicle may include: the speed and position of the first target vehicle are used to determine whether the first target vehicle deviates from the driving lane of the host vehicle.

Sensing the distance to the front object may include: the distance to the object in front is sensed using a lidar. Determining the preceding vehicle and the further preceding vehicle using the sensor of the own vehicle may further include: acquiring a front image; and determines the traveling lane of the own vehicle from the front image.

According to the present disclosure, the traveling speed of the own vehicle is determined using the traveling information of the first target vehicle and the second target vehicle when the CACC system is executed, so that the traveling safety can be further improved. In particular, even if the first target vehicle suddenly changes lanes in a state where the second target vehicle, not the first target vehicle, travels at a low speed, the travel speed is determined according to the travel information of the second target vehicle, so that a safe driving environment can be provided to the driver.

It is to be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory and are intended to provide further explanation of the disclosure as claimed.

Drawings

The above and other objects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an exemplary diagram of a CACC system to which the present disclosure is applied;

FIG. 2 is a diagram showing a region of interest (ROI) of a CACC system on a straight road;

fig. 3 is a block diagram illustrating a configuration of a CACC system according to an embodiment of the present disclosure;

fig. 4 is a diagram illustrating state transitions of a CACC system 300 according to an embodiment of the present disclosure;

fig. 5 is a diagram illustrating a travel speed control process of the CACC system according to an embodiment of the present disclosure;

fig. 6A and 6B are diagrams illustrating sensing results of a front vehicle Cp1 and a forward (far-forward) vehicle Cp2 according to the position of the front vehicle Cp 1;

fig. 7 is a diagram illustrating a case where the preceding vehicle Cp1 is changing lanes to the right lane;

fig. 8 is a diagram illustrating the sensing results of a preceding vehicle on a curved traveling lane and a further preceding vehicle according to the position of the preceding vehicle;

fig. 9 is a flowchart illustrating a case where the CACC system controls the traveling speed of the own vehicle according to the embodiment of the present disclosure.

FIG. 10 is a flow chart illustrating a situation where a CACC system uses sensors of the host vehicle to determine a lead vehicle and a further lead vehicle according to an embodiment of the present disclosure;

FIG. 11 is a flow chart illustrating a situation where the CACC system uses the sensors of the host vehicle to determine the vehicle ahead and the vehicles further ahead on a straight-driving lane according to an embodiment of the present disclosure; and

fig. 12 is a flowchart illustrating a case where the CACC system determines a preceding vehicle and a preceding vehicle using a sensor of the own vehicle on a curved traveling lane according to an embodiment of the present disclosure.

Detailed Description

It is understood that the term "vehicle" or "vehicular" or other similar terms as used herein include motor vehicles in general, such as passenger vehicles including Sport Utility Vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuel from non-petroleum sources). As referred to herein, a hybrid vehicle is a vehicle having two or more power sources, such as gasoline-powered and electric-powered vehicles.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Throughout this specification, unless explicitly described to the contrary, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. In addition, the terms "unit", "device", "means" and "module" described in the specification mean a unit for processing at least one function and operation, and may be implemented by hardware components or software components and combinations thereof.

Further, the control logic of the present disclosure may be embodied as a non-transitory computer readable medium on a computer readable medium containing executable program instructions executed by a processor, controller, or the like. Examples of computer readable media include, but are not limited to, ROM, RAM, compact Disc (CD) -ROM, magnetic tape, floppy disk, flash drive, smart card, and optical data storage device. The computer readable medium CAN also be distributed over network coupled computer systems so that the computer readable medium is stored and executed in a distributed fashion, such as by a telematics server or a Controller Area Network (CAN).

Unless specifically defined, all terms (including technical and scientific terms) used in the specification may be used as commonly understood by one of ordinary skill in the art to which this disclosure belongs. In addition, terms that are commonly used but are not defined in dictionaries may not be interpreted ideally or excessively if not explicitly and specifically defined.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The matters defined in the description, such as detailed construction and elements, are nothing but specific details provided to assist those of ordinary skill in the art in a comprehensive understanding of the disclosure. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in various forms.

First, the definitions will apply to the definitions of the specification provided herein.

A preceding vehicle: a vehicle moving in the same direction in front of the host vehicle and along the same road of the host vehicle.

The vehicle further ahead: a vehicle located in front of the preceding vehicle and moving in the same direction along the same road of the own vehicle and the preceding vehicle.

Spacing: the distance between the tip of the leading vehicle and the front of the own vehicle.

Region of interest: the area in which the potential vehicle of interest and the target vehicle exist, which will be described later, and may have an influence on the control of the CACC system provided in the own vehicle.

Vehicle of potential interest: a vehicle that exists in the region of interest and performs V2V communication with the own vehicle.

A target vehicle: a vehicle that follows the own vehicle and may or may not be connected to the own vehicle through V2V communication.

Time interval: a value calculated from the speed of the own vehicle and the interval between the own vehicle and the preceding vehicle (time interval = interval/speed).

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

Fig. 1 is an exemplary diagram of a CACC system to which the present disclosure is applied.

As shown in fig. 1, the CACC system 300 applied to the present disclosure is a system in which wireless communication with a preceding vehicle and/or infrastructure is added in order to enhance the sensing capability of the ACC system in the related art. The CACC system 300 may receive road speed limits, time intervals (time difference between the vehicle and the vehicle in front), and/or other standard messages from Road Side Equipment (RSE) using V2I communications. That is, the CACC system 300 of the vehicle may receive an input of information, such as a recommended set speed or time interval, from the regional traffic control system through V2I communication. Further, the CACC system may receive the nearby vehicle information including the traveling information (speed and acceleration) of the nearby vehicle 20 through V2V communication with at least one nearby vehicle 20, or may transmit its own vehicle information to the nearby vehicle 20. Further, the CACC system may acquire vehicle information of a vehicle that may be ahead of the own vehicle using a sensor in the related art.

In this case, the traveling vehicle information may include a vehicle Identification (ID) for distinguishing from other vehicles, a vehicle shape, a size, a braking performance, vehicle source information including a total vehicle weight, vehicle position information represented by 3D coordinates of latitude, longitude, and altitude, a vehicle forward-travel angle measured with reference to the true north direction, a vehicle speed, an acceleration, a yaw rate, a braking state, a throttle position, and a steering angle.

Further, the CACC system may receive an input of a set speed or time interval from a driver through a Driver Vehicle Interface (DVI) 60, and may inform the driver of status information of the CACC system. Further, the CACC system may acquire vehicle information 50 from various sensors or control devices disposed inside the vehicle. The CACC system may control the speed of the vehicle by controlling a throttle or a brake based on various types of data collected by the above-described method.

As described above, by information acquisition of V2V communication and/or V2I communication, the CACC system can more accurately control the time interval with the preceding vehicle while maintaining smooth driving behavior, and can respond to speed changes of a plurality of preceding vehicles quite quickly. Furthermore, the CACC system has an advantage in that it can set a shorter time interval without impairing safety or the driver's sense of stability.

Fig. 2 is a diagram showing a region of interest (ROI) of the CACC system on a straight road.

The CACC system may be interested only in surrounding vehicles entering a region of interest (ROI). Information from vehicles beyond the ROI may be considered meaningless information in controlling the vehicles. Therefore, the CACC system can perform a control operation using only information from the vehicle located within the region of interest to reduce the load applied to the CACC system.

Referring to fig. 2, the regions of interest may be set to have lengths of about 16m and about 32m in the left-right direction, respectively, with reference to the center of the vehicle in which the CACC system is installed. Further, the region of interest may be set to have a length of about 250m in the front direction and a length of about 100m in the rear direction, centered on the driver seat. In the case of a curved road, the region of interest may be set to curve the region of interest set on a straight road to match the curvature of the curved road.

Further, the CACC system may set a target vehicle and a vehicle of potential interest (PVOI). The target vehicle is a preceding vehicle which is followed by the vehicle equipped with the CACC system. That is, the CACC system uses the distance held between the own vehicle and the target vehicle in calculating the time interval, and the target vehicle becomes the target of the constant holding time interval. A vehicle of potential interest refers to a vehicle that is within the area of interest and is connected to the CACC system via V2V communication. The vehicle of potential interest may be a vehicle that has an effect on the speed control of the host vehicle in which the CACC system is installed. A vehicle that is located in a side lane and is expected to merge into the lane of the host vehicle, or a vehicle that is located in the same lane as the host vehicle and the target vehicle and is ahead of the target vehicle, may be a vehicle of potential interest, and the vehicle of potential interest may become the target vehicle.

Fig. 3 is a block diagram illustrating a configuration of a CACC system according to an embodiment of the present disclosure.

Referring to fig. 3, the CACC system according to the present disclosure may include an information collection unit 310, a communication unit 320, a DVI unit 340, and a control unit 330. The control unit (or "controller") 330 may include a state management unit 331, a travel management unit 333, and a target vehicle selection unit 335, and may further include a profile management unit 337.

The communication unit 320 may receive a road speed limit, a time interval (time difference between the host vehicle and the preceding vehicle), and/or other standard messages from the RSE 10 based on the V2I communication. That is, the CACC system 300 of the vehicle may receive not only the recommended set speed or time interval information from the regional traffic control system through V2I communication, but also information about roads, traffic, weather, and the like. Further, the communication unit 320 may receive the nearby vehicle information including the traveling information (speed and acceleration) of the nearby vehicle 20 through V2V communication with at least one nearby vehicle 20, or may transmit its own vehicle information to the nearby vehicle 20. In particular, in this case, the communication unit may provide not only the own travel information but also the identification information or the travel information of the preceding vehicle to the nearby vehicle 20. In the case where the nearby vehicle provides only the identification information, the communication unit may acquire the vehicle information of the vehicle ahead of the nearby vehicle that has transmitted the identification information, using information from the nearby vehicle having the identification information. Therefore, even for the target vehicle and the vehicle ahead of the target vehicle, the own vehicle can acquire the vehicle information. On the other hand, in the case where only the identification information is transmitted, the amount of data transmitted by each vehicle can be reduced.

Further, the information collection unit 310 may collect own vehicle information required to control the CACC system and surrounding environment information collected using sensors. The own vehicle information may include own vehicle running speed, throttle and brake control information, and the surrounding environment information may include information of the nearby vehicle 20 collected by the sensors. In particular, if there is a target vehicle ahead of the own vehicle, the information collection unit may collect the surrounding environment information by calculating the travel speed and the separation distance of the target vehicle based on the radar or the lidar.

The DVI unit 340 may receive setting information input from the driver through the driver-vehicle interface and may transmit information (e.g., status information of the CACC system 300 and warning information that may be generated by the CACC system 300) required to be notified to the driver. As an example, the driver may input a target speed and/or a target time interval through the DVI unit 340, and the CACC system 300 may operate the vehicle to match the input target speed and/or the target time interval. As another example, which will be described later, the driver may be notified of status information about whether the CACC system is in an off state, a standby state, or an active state through the DVI unit 340.

Furthermore, the CACC system may further comprise a drive unit (not shown). The driving unit may control the throttle and/or the brake according to a control signal of the control unit 330 described later.

The control unit 330 may control the traveling speed of the own vehicle based on the information acquired by the information collection unit 310 and the communication unit 320. That is, the control unit 330 may select the target vehicle to be followed by the own vehicle based on the vehicle information of the nearby vehicle acquired by the communication unit 320 and the travel information of the preceding vehicle collected by the information collection unit 310, and may control the travel speed of the own vehicle based on the target speed of the own vehicle if the target vehicle to be followed by the own vehicle is not selected, and may control the travel speed of the own vehicle based on the speed information of the target vehicle, the speed information of the own vehicle, and the target time interval if the target vehicle to be followed by the own vehicle is selected. In this case, the user may set the target speed and the target time interval, or the CACC system may automatically set the target speed and the target time interval to match the situation based on the information acquired by the information collecting unit 310 and the communication unit 320.

In order to perform the above-described functions, the control unit 330 may include a state management unit 331, a travel management unit 333, and a target vehicle selection unit 335.

The target vehicle selection unit 335 may select a potential vehicle of interest and a target vehicle based on the vehicle information of the plurality of nearby vehicles 20 obtained through the communication unit 320. The potentially interesting vehicle refers to a nearby vehicle present in the area of interest as described above. If the nearby vehicle is within the area of interest based on the position information received from the nearby vehicle and the position information of the own vehicle, the corresponding nearby vehicle may be selected and registered as a potential vehicle of interest. In addition, a preceding vehicle located just in front of the own vehicle among the vehicles of potential interest may be selected as the target vehicle. In particular, in the case of a target vehicle, the target vehicle needs to be verified with very high reliability, and therefore the target vehicle can be selected by verifying three conditions based on the preceding vehicle information collected by the information collection unit 310 as follows.

1. Using the position information of the potential vehicles of interest, potential vehicles of interest traveling in the same lane as the own vehicle (hereinafter referred to as "first group of potential vehicles of interest") are selected.

2. The following potential vehicles of interest (hereinafter referred to as "second group of potential vehicles of interest") are selected, in which the presence range information received from each potential vehicle of interest in the first group of potential vehicles of interest is within the larger of (0.1 × (range measured by sensor)) and (0.7 × (length of each potential vehicle of interest)). In this case, if the length of the potential vehicle of interest is unknown, the value of (0.7 × (length of each potential vehicle of interest)) may be about 3.3m.

3. Vehicles of potential interest (hereinafter referred to as "third set of vehicles of potential interest") are selected in which the difference between the speed information received from each vehicle of potential interest in the second set of vehicles of potential interest and the speed measured by the sensor is within 1 m/s.

Generally, only one vehicle of potential interest is included in the third set of vehicles of potential interest selected by verifying the three conditions. However, in the case where two or more potential vehicles of interest are included in the third group of potential vehicles of interest, a potential vehicle of interest at the closest position may be selected as the target vehicle based on the position information of each potential vehicle of interest in the third group of potential vehicles of interest.

The above-described condition verification can be performed more accurately by comparing and determining accumulated sample data, rather than comparing and determining one sample data.

As an example, after calculating the correlation coefficient based on the following equation 1 and equation 2, it may be determined whether the potential vehicle of interest is the target vehicle based on the calculated correlation coefficient.

[ equation 1]

V _TV (N)＝V _i (N)+a _i (N)Δt

→V _TV (N)-V _i (N)＝a _i (N)Δt→ΔV _i (N)＝a _i (N)Δt

Here, N denotes the number of samples for measuring the amount of change in speed and acceleration, V _TV (N) denotes the speed of the Nth sample of the target vehicle calculated based on the radar, V _i (N) represents the speed of the nth sample in the traveling information received from the nearby vehicle i. a is _i (N) represents the acceleration of the nth sample in the traveling information received from the nearby vehicle i, and Δ t represents the time difference between the sample value based on the traveling information received from the nearby vehicle i and the radar-based speed sample value.

[ formula 2]

Δ V for N samples _i Average value of (2)

A for N samples _i Average value of (2)

Here, if r satisfies-1-r-n 1 and is close to 1, the correlation becomes high, and therefore the corresponding vehicle can be verified as the target vehicle.

If the target vehicle selection unit 335 determines the presence/absence of a target vehicle or a vehicle of potential interest, such information may be communicated to the state management unit 331, the travel management unit 333, and/or the profile management unit 337 for purposes of matching the functions.

The state management unit 331 may manage the state of the CACC system. The CACC system may be in an off state, a standby state, or an active state depending on the state of the subject vehicle and the presence/absence of the target vehicle and/or the vehicle of potential interest.

Fig. 4 is a diagram illustrating state transitions of a CACC system according to an embodiment of the present disclosure.

Referring to fig. 4, the CACC system may include a off state 400 in which the CACC system is not operated, a standby state 500 in which the CACC system is operated but does not control the traveling speed of the own vehicle, and an active state 600 in which the traveling speed of the own vehicle is controlled. In particular, the activation state 600 may include an ACC activation state 610 in which the traveling speed of the own vehicle is controlled using only information acquired from the own vehicle in a state where there is no vehicle connected by V2V communication in the area of interest, and a cooperative activation state 620 in which there is a nearby vehicle connected by V2V communication in the area of interest and the traveling speed of the own vehicle is controlled using information from the nearby vehicle acquired by V2V communication and the information acquired from the own vehicle.

The off state 400 is a state where the CACC system is not operating. That is, in the closed state 400, the CACC system does not perform any function. The CACC system may be transitioned to the off state 400 by a stall of the vehicle or a manual operation by the driver.

The standby state 500 is a state in which the CACC system is to be activated, and in the standby state 500, the CACC system does not perform speed control. If the own vehicle is started, the CACC system may be shifted to the standby state 500 after the self-diagnosis is automatically completed in the off state 400, or may be shifted from the off state 400 to the standby state 500 by a manual operation of the driver. Further, if a driver's manual control input (e.g., brake or throttle control) is received in the active state 600, the CACC system may transition to the standby state 500.

The active state 600 is a state in which the CACC system is activated to perform speed control. As described above, the activation state 600 may include an ACC activation state 610 and a co-activation state 620. If there is no potential vehicle of interest or target vehicle connected via V2V communication, the CACC system operates in ACC active state 610, whereas if there is a potential vehicle of interest or target vehicle connected via V2V communication, the CACC system operates in coordinated active state 620. If the speed of the host vehicle becomes higher than a predetermined speed (hereinafter referred to as "first speed") in the standby state 500, the CACC system may transition to the active state 600. In addition, if the speed of the own vehicle is lower than the first speed in the active state 600, the CACC system may prohibit acceleration or may shift to the standby state 500.

When the CACC system transitions to the active state 600, it may first operate in the ACC active state 610. In the ACC active state 610, cruise control may be performed to match the highest speed set as in the ACC system in the related art, or if there is a preceding vehicle, follow control may be performed. In the ACC active state 610, if there is a potential vehicle of interest or target vehicle connected through a V2V communication, and the data received from the potential vehicle of interest or target vehicle is reasonable, the CACC system may be transitioned to the coordinated active state 620. In one embodiment of the present disclosure, if the information about the potential vehicle of interest or the target vehicle received using V2V communication coincides with the vehicle information acquired by the sensor of the own vehicle through the information collecting unit 310, the data may be confirmed to be reasonable. Such verification may be performed by the target vehicle selection unit 335.

In addition, if there is no potential vehicle of interest or target vehicle in the cooperative active state 620, the CACC system may transition to the ACC active state 610, and may transition to the ACC active state 610 even if V2V communication is not performed or only unreasonable data is received.

The coordinated activation state 620 of the CACC system may include a non-following mode 621, a near-following mode 622, and a following mode 623. The non-following mode 621 is a mode performed in the following case: wherein the vehicle of potential interest is connected by V2V communication, but the target vehicle is not present, and the speed control of the own vehicle by the CACC system may be affected by data received from the vehicle of potential interest.

The near following mode 622 is a mode performed in the following case: among them, there are target vehicles connected through V2V communication, and in this case, speed control of the own vehicle by the CACC system may be affected by information from the connected target vehicles and potential vehicles of interest.

The following mode 623 is a mode performed in the following case: where the target vehicle is present but not connected by V2V communication. In this case, the target vehicle may be sensed by the sensor of the own vehicle, and such information may be acquired by the information collecting unit 310. In this case, the speed control of the own vehicle by the CACC system may be affected by information from the connected potential vehicle of interest and the target vehicle sensed by the sensor.

The CACC system may operate in one of the three modes described above in the cooperative active state 620, and may determine the three modes according to whether the target vehicle is present and whether the target vehicle is connected through a V2V communication.

That is, referring to fig. 4, if there is no target vehicle in the area of interest, but there is a potential vehicle of interest in the cooperative activation state 620, the CACC system may transition to (a) the non-following mode 621, and if there is a target vehicle connected through V2V communication, the CACC system may transition to (B) the near-following mode. If there is a target vehicle in the area of interest that is not connected through V2V communication and there are also potentially interesting vehicles in the area of re-interest, the CACC system may transition to (C) follow mode 623.

If neither a connected target vehicle nor a vehicle of potential interest is present, the CACC system may transition to ACC active state 610.

The maximum and minimum requirements for each mode that can be controlled in the active state 600 of the CACC system may be defined as in table 1 below.

[ Table 1]

Referring to table 1, the CACC system cannot set the minimum time interval to 0.5s or less, cannot execute deceleration control of 5m/s ^2 or more through maximum brake control, and cannot execute acceleration control of 2.75m/s ^2 or more through throttle control.

Referring again to fig. 3, the state management unit 331 may manage the state of the CACC system 300 according to the above-described method, and if the CACC system 300 is in an active state, the travel management unit 333 may control the travel speed of the own vehicle. In the case of the CACC system 300, the running speed is generally controlled so that the driver can perform driving to match the set target speed. However, if there is a target vehicle, the running speed may be controlled so that the own vehicle can follow the target vehicle.

The travel management unit 333 may control the travel speed of the own vehicle based on the state information of the state management unit 331 and the presence/absence of the target vehicle and/or the potential vehicle of interest from the target vehicle selection unit 335. In particular, in order to seek a safer driving environment for the driver, not only the target vehicle of the host vehicle 700 but also the travel information of the target vehicle may be used to control the travel speed.

Hereinafter, travel control in the CACC system 300 in consideration of travel information of the target vehicle will be described in more detail with reference to fig. 5.

Fig. 5 is a diagram illustrating a travel speed control process of the CACC system according to an embodiment of the present disclosure.

Referring to fig. 5, the driving queue in the same lane includes a front vehicle (front vehicle) Cp2, a front vehicle Cp1 that may be a target vehicle of the own vehicle 700, and the own vehicle 700 in this order. Here, the front vehicle Cp2 may be a target vehicle of the front vehicle Cp1. Here, since the vehicle Cp3 is not traveling in the same lane as the lane of the host vehicle 700, it may be a potentially interested vehicle, but may not be a target vehicle.

The vehicles 700, cp1, cp2, and Cp3 may transmit/receive their travel information through V2V communication. Specifically, the respective vehicles may transmit an Identifier (ID) of their target vehicle together when transmitting their own travel information. That is, since the vehicle Cp2 does not have a target vehicle traveling ahead thereof, it transmits only its own traveling information, and if the vehicle Cp2 becomes a target vehicle of the vehicle Cp1, the vehicle Cp1 can transmit an ID (e.g., ID-2) of its target vehicle together with its own traveling information. Therefore, the own vehicle 700 can receive the ID information (for example, ID-2) of the vehicle Cp2 as the target vehicle of the vehicle Cp1 and the traveling information of the vehicle Cp1 as the target vehicle of the own vehicle 700. In this case, the travel management unit 333 of the CACC system 300 mounted on the own vehicle 700 may know the target vehicle Cp2 of the target vehicle Cp1 using the received ID information, and may control the travel speed of the own vehicle 700 using the travel information received from the vehicle Cp1 and the travel information received from the vehicle Cp2.

More specifically, in order to accurately select the target vehicle, the target vehicle selection unit 335 may use the data received by the communication unit 320 from the nearby vehicle and the preceding vehicle information collected by the information collection unit 310. That is, the target vehicle selection unit 335 may select the target vehicle only in the case where the two pieces of information coincide with each other or the above-described verification condition is satisfied. In particular, in the case of controlling the speed based on not only the traveling information of the target vehicle but also the traveling information of the target vehicle, the target vehicle of the target vehicle should be accurately confirmed.

Hereinafter, a method for verifying a target vehicle (first target vehicle) of the own vehicle and a target vehicle (second target vehicle) of the target vehicles will be described in more detail. Since the nearby vehicle information received through the communication unit 320 among the information required in the target vehicle selection unit 335 can be immediately acquired through V2V communication, the collection of information of a preceding vehicle, which may be a first target vehicle, and a further preceding vehicle, which may be a second target vehicle, performed by the information collection unit 310 will be described in more detail.

The information collection unit 310 may collect information of the preceding vehicle and the more preceding vehicles using the camera and/or the distance sensor 311.

The camera may acquire a forward image in order to determine the driving lane W of the host vehicle 700. The front image acquired by the camera may include a lane W in which the host vehicle is traveling and a lane L forming the lane. The camera may be mounted on the front of the vehicle and may include an image sensor, such as a Charge Coupled Device (CCD) or a Complementary MOS (CMOS).

The distance sensor 311 may sense an object located in front of the host vehicle 700, for example, a front vehicle Cp1 and a further front vehicle Cp2 traveling in front of the host vehicle 700, a stopping object including a structure installed around a road, and a vehicle heading for a lane. Further, the distance sensor 311 may sense the distance to an object in front of the host vehicle 700, and may also sense the speed and acceleration in the case of a moving object.

For this purpose, the distance sensor 311 may be implemented by radar or light detection and ranging (lidar). If the distance sensor 311 is implemented by a laser radar, it may irradiate a predetermined front area with laser light and may receive the laser light reflected from a front object. Upon receiving the laser light, the distance sensor 311 may sense physical properties of the front object, such as the distance, speed, and shape of the front object, from the laser light reception time and intensity, the frequency change, and the polarization state change. Hereinafter, for convenience of explanation, it is assumed that the distance sensor 311 is implemented by a laser radar.

Fig. 6A and 6B are diagrams illustrating the sensing results of the front vehicle Cp1 and the further front vehicle Cp2 according to the position of the front vehicle Cp1. In fig. 6A and 6B, the hatched area is an area where the distance sensor 311 is irradiated with laser light.

If there are the front vehicle Cp1 and the further front vehicle Cp2 in the driving lane W, as shown in fig. 5, the distance sensor 311 of the host vehicle 700 may sense the front vehicle Cp1 by irradiating laser light in the front direction. The distance sensor 311 may sense the rear of the preceding vehicle Cp1 if the preceding vehicle Cp1 is traveling in the same direction as the traveling direction of the own vehicle 700. Further, if the preceding vehicle CP1 is located in the traveling path where the laser light is irradiated, the distance sensor 311 may not sense the further preceding vehicle CP2 that is blocked by the preceding vehicle CP1.

On the other hand, the front vehicle Cp1 may escape from the traveling lane W to change lanes. Referring to fig. 6a, d1 denotes a rear region of the front vehicle Cp1 sensed by the distance sensor 311, and d2 denotes a rear region of the further front vehicle Cp2 sensed by the distance sensor 311.

Here, d2 may be changed according to the position of the front vehicle Cp1. Fig. 6B illustrates a case where the front vehicle Cp1 moves further rightward as compared with the case illustrated in fig. 6A. In this case, it can be confirmed that the rear region of the more forward vehicle Cp2 sensed by the distance sensor 311 is different from that shown in fig. 6A.

The sensing result of the distance sensor 311 may be used for the target vehicle selection unit 335 to determine the presence of the first target vehicle Cp1 and the further front vehicle Cp2.

The target vehicle selection unit 335 may determine the presence of the preceding vehicle Cp1 and the further preceding vehicle Cp2 traveling on the same lane as the traveling lane W based on the sensing result of the distance sensor 311. As described above, since the preceding vehicle Cp1 and the further preceding vehicle Cp2 should travel on the same lane as the traveling lane W, the target vehicle selection unit 335 may first determine the traveling lane W.

For this, the target vehicle selection unit 335 may use the front image acquired by the camera 200. The target vehicle selection unit 335 may process the front image so that the lane L is clearly displayed in the front image. By so doing, the target vehicle selection unit 335 may extract the left and right lines L closest to the center of the front image, and may determine the lane formed by the lines as the driving lane W.

If the traveling lane W is determined, the target vehicle selection unit 335 may determine whether an object located in the traveling lane W among the preceding objects sensed by the distance sensor 311 is the preceding vehicle Cp1 or the further preceding vehicle Cp2. Specifically, the target vehicle selection unit 335 may first determine the presence of the preceding vehicle Cp1, and may then use the determined position of the preceding vehicle Cp1 to determine the presence of the further preceding vehicle Cp2.

To determine the preceding vehicle Cp1, the target vehicle selection unit 335 may use a predetermined first reference width. Here, the first reference width may represent a minimum width that can be determined as the preceding vehicle Cp1 among the objects sensed by the distance sensor 311. The first reference width may be stored in advance in a storage unit described later, or may be determined in advance by an input of a user or an operation of the target vehicle selection unit.

The distance sensor 311 may sense the rear of the preceding vehicle Cp2 if the preceding vehicle Cp1 is traveling in the same direction as the traveling direction of the own vehicle 700, or the traveling direction of the preceding vehicle Cp1 is not significantly deviated from the traveling direction of the own vehicle 700. Referring to fig. 6A, the distance sensor 311 may sense a rear region d1 of the front vehicle Cp1, and d1 may be indicated in a straight line manner. In this case, d1 may represent the width of the front vehicle Cp1.

In contrast, if the preceding vehicle Cp1 deviates significantly from the traveling direction of the own vehicle 700, the distance sensor 311 may sense a part of the rear and side portions of the preceding vehicle Cp1. Referring to fig. 6B, the distance sensor 311 may sense a rear region and a partial side region d1 of the front vehicle Cp1, and d1 may be represented as an "L" shape. In this case, the length of one of the two straight lines forming the "L" shape d1 may indicate the width of the front vehicle Cp1.

Therefore, the target vehicle selection unit 335 may determine the presence of the preceding vehicle Cp1 by confirming whether the width of the object detected in the driving lane W is equal to or greater than the first reference width. Specifically, the target vehicle selection unit 335 may confirm whether the width of the detected object is equal to or greater than the first reference width in the order closest to the front. As a result, the target vehicle selection unit 335 may determine the object closest to the front and having a width equal to or greater than the first reference width as the preceding vehicle Cp1.

If the preceding vehicle Cp1 is determined, the target vehicle selection unit 335 may determine the further preceding vehicle Cp2 based on the position of the preceding vehicle Cp1. As described above with reference to fig. 6A and 6B, the sensing area d2 of the further front vehicle Cp2 changes according to the position of the front vehicle Cp1, and therefore the target vehicle selection unit 335 may determine the further front vehicle Cp2 according to the determined position of the front vehicle Cp1.

Specifically, the target vehicle selection unit 335 may determine an object having a width equal to or greater than a second reference width determined from the position of the preceding vehicle Cp1 as the further preceding vehicle Cp2. For this, the target vehicle selection unit 335 may first determine the second reference width using the position of the preceding vehicle Cp1.

Fig. 7 is a diagram illustrating a case where the front vehicle Cp1 changes the lane to the right lane. Referring to fig. 7, a method for determining the second reference width will be described. In fig. 7, it is assumed that the position of the distance sensor 311 irradiated with laser light is the origin.

First, the target vehicle selection unit 335 acquires the left rear corner coordinates P1 (preV _ x, preV _ y) of the preceding vehicle Cp1. As shown in fig. 6A, if the sensing region d1 where the front vehicle Cp1 is sensed is a straight line, the target vehicle selection unit 335 may set the left end of the straight line d1 to P1. Unlike this, if the sensing region d1 where the preceding vehicle Cp1 is sensed is in the shape of "L", the target vehicle selecting unit 335 may set the vertex of d1 to P1.

Next, the target vehicle selection unit 335 acquires the left rear corner coordinates P2 (pre _ preV _ x, pre _ preV _ y) of the further forward vehicle Cp2, assuming that the further forward vehicle Cp2 is located on the rightmost side of the traveling lane W of the further forward vehicle Cp2.

After acquiring P1 and P2, the target vehicle selection unit 335 may acquire an intersection P3 (intersect _ X, intersect _ y) between a straight line from the origin to P1 and X = pre _ preV _ X.

Finally, the target vehicle selection unit 335 may determine the distance between P2 and P3 as the second reference width k. Specifically, the target vehicle selection unit 335 may acquire the second reference width k according to the following equation 3.

[ formula 3]

k＝abs(intersect_x-pre_preV_x)

Here, k denotes the second reference width, intersector _ x denotes the x-coordinate of P3, and pre _ preV _ x denotes the x-coordinate of P2.

The description so far is made on the assumption that the preceding vehicle CP1 changes its lane to the right. However, even in the case where the preceding vehicle Cp1 changes the lane to the left side, the second reference width may be acquired in a similar manner.

After acquiring the second reference width, the target vehicle selection unit 335 may determine an object having a width equal to or greater than the second reference width among the objects sensed in the driving lane W as the further preceding vehicle Cp2. In one embodiment, the target vehicle selection unit 335 of the own vehicle 700 may determine an object having a width equal to or larger than the second reference width at a time as the further front vehicle Cp2.

Further, in another embodiment, the target vehicle selection unit 335 of the own vehicle 700 may determine an object having a width equal to or larger than the second reference width during the predetermined reference time as the further preceding vehicle Cp2. This can improve the accuracy of determination of the further front vehicle Cp2.

In particular, the target vehicle selection unit 335 may determine an object, which has a width equal to or greater than the second reference width during a predetermined reference time and senses an increase in the width, as the more preceding vehicle Cp2. As shown in fig. 6A and 6B, the sensing area d2 of the front vehicle Cp2 may increase as the lane change of the front vehicle Cp1 progresses. Therefore, the target vehicle selecting unit 335 can more easily determine the presence of the preceding vehicle Cp2 when the preceding vehicle Cp1 deviates from the traveling lane W in consideration of whether the width is increased.

Further, if a plurality of objects having a width equal to or greater than the second reference width are sensed, the target vehicle selection unit 335 may determine an object closest to the determined preceding vehicle Cp1 as a further preceding vehicle Cp2. As described above, since the more-ahead vehicle Cp2 should become the target vehicle of the preceding vehicle Cp1, the target vehicle selection unit 335 may determine an object located immediately ahead of the preceding vehicle Cp1 among objects having a width equal to or greater than the second reference width as the more-ahead vehicle Cp2.

If the preceding vehicle Cp1 and the further preceding vehicle Cp2 are determined, when they pass the above-described verification using the nearby vehicle information acquired by the communication unit 320 and the information of the preceding vehicle Cp1 and the further preceding vehicle Cp2 collected using the sensors of the own vehicle 700 as described above, the target vehicle selection unit 335 may determine the preceding vehicle Cp1 and the further preceding vehicle Cp2 as the first target vehicle and the second target vehicle, and therefore, the selection reliability may be improved.

The travel management unit 333 may control the driving unit to perform travel at a travel speed determined according to the travel information of the first target vehicle Cp1 and the second target vehicle Cp2 if the target vehicle selection unit 335 selects the first target vehicle Cp1 and the second target vehicle Cp2. Here, the travel information may include various information related to travel, such as speed, acceleration, and position.

For this, the travel management unit 333 may acquire the first travel speed corresponding to the travel information of the first target vehicle Cp1 and the second travel speed corresponding to the travel information of the second target vehicle Cp2 through the information collection unit 310 and/or the communication unit 320. Specifically, the travel management unit 333 may acquire a first travel speed that can maintain a first safe distance from the first target vehicle CP1, and may acquire a second travel speed that can maintain a second safe distance from the second target vehicle CP2.

Finally, the travel management unit 333 may control the drive unit to perform travel according to any one of the first travel speed and the second travel speed. Specifically, the travel management unit 333 may control the drive unit to perform travel according to one of the first travel speed and the second travel speed having a smaller value.

By so doing, even if the first target vehicle Cp1 deviates from the lane, the CACC system 300 according to the disclosed embodiment may control the own vehicle 700 to travel by maintaining a safe distance with respect to the second target vehicle Cp2.

On the other hand, the travel management unit 333 may control the drive unit to perform travel at a travel speed determined from the travel information of the first target vehicle Cp1 and the second target vehicle Cp2 only in the case where the first target vehicle Cp1 deviates from the travel lane W. In order to determine whether the first target vehicle Cp1 deviates from the traveling lane W, the traveling management unit 333 may use the speed and position of the first target vehicle Cp1. Specifically, the travel management unit 333 may determine whether the first target vehicle Cp1 deviates from the lane using the speed and position of the first target vehicle Cp1 with respect to the lane L forming the traveling lane W acquired through the front image.

By so doing, the own vehicle 700 according to the disclosed embodiment can determine a running speed that is adaptive to whether the first target vehicle Cp1 deviates from the lane.

The description so far is made on the assumption that the lane W has a straight line or a curvature similar to a straight line. Unlike this, even in the case where the traveling lane W has a large curvature, the target vehicle selection unit 335 may select the first target vehicle and the second target vehicle by sensing the preceding vehicle and the further preceding vehicle in a similar manner.

Fig. 8 is a diagram illustrating the sensing results of the preceding vehicle and the further preceding vehicle according to the position of the preceding vehicle on the curved travel lane.

The host vehicle 700 traveling in the curved traveling lane W may have a higher risk of accident than the straight traveling lane W. Therefore, during traveling in the curved traveling lane W, the own vehicle 700 needs to determine the traveling speed in consideration of not only the traveling speed of the preceding vehicle Cp1 but also the traveling speed of the further preceding vehicle Cp2.

If the driving lane W is determined, the target vehicle selection unit 335 may determine whether the curvature of the driving lane W is equal to or greater than a predetermined reference curvature. Here, the predetermined reference curvature may represent a minimum curvature that the curved running lane W has.

The target vehicle selecting unit 335 may determine the further front vehicle Cp2 by a method corresponding to the curved traveling lane W if the curvature of the traveling lane W is equal to or greater than a predetermined reference curvature. After determining the preceding vehicle Cp1 according to the method described above with reference to fig. 6A, 6B, and 7, the target vehicle selection unit 335 may determine an object, of the objects having a width equal to or greater than the second reference width, whose surfaces are sensed by the distance sensors, as a further preceding vehicle Cp2.

Referring to fig. 8, in the case of traveling in the curved traveling lane W, the sensing region d2 of the vehicle Cp2 further ahead by the distance sensor may be formed in an "L" shape. In other words, the distance sensor may sense the rear and one side of the second target vehicle Cp2 in the curved running lane W.

By the above method, the target vehicle selection unit 335 may sense the preceding vehicle Cp1 and the further preceding vehicle Cp2, and if the first target vehicle and the second target vehicle are selected based on the sensed vehicles, the travel management unit 333 may determine the travel speed by the above method.

As such, by taking into account the curvature of the traveling lane W, the host vehicle according to the disclosed embodiment can determine the traveling speed for ensuring a safe distance even in the case of traveling in a curved lane.

Referring again to fig. 3, information for controlling the own vehicle 700 may be stored in a storage unit (not shown) in advance. For example, the first reference width for determining the preceding vehicle Cp1 may be stored in the storage unit in advance. Further, an algorithm for obtaining the second reference width for determining the further-ahead vehicle Cp2 may be stored in the storage unit in advance. Further, the reference curvature for determining the curved traveling lane W or the above-described reference time may be stored in the storage unit in advance.

Fig. 9 is a flowchart illustrating a case where the CACC system 300 controls the traveling speed of the own vehicle according to the embodiment of the present disclosure.

Referring to fig. 9, the cacc system 300 may acquire vehicle information of the nearby vehicle using V2V communication (S100). The vehicle information may include information such as GPS position information, speed, and acceleration, and may also include information about the road on which each nearby vehicle travels.

Further, the CACC system 300 may determine a preceding vehicle and a further preceding vehicle traveling ahead of the own vehicle 700 using a camera or a distance sensor mounted to the own vehicle 700 (S200). Further, the CACC system may determine the first target vehicle and the second target vehicle by comparing the nearby vehicle information acquired through the V2V communication with the preceding vehicle and the further preceding vehicle determined using the sensor of the own vehicle (S300). Here, the first target vehicle may be a target vehicle to be followed by the host vehicle 700, and the second target vehicle may be a target vehicle to be followed by the first target vehicle. After the first and second target vehicles are determined as described above, the CACC system 300 may determine the traveling speed of the own vehicle using the traveling information of the first and second target vehicles (S400), and may control the traveling of the own vehicle according to the determined traveling speed (S500). Here, the travel information may be all types of information related to the first target vehicle and the second target vehicle, including speed, acceleration, and position.

The CACC system 300 according to the disclosed embodiment may secure safety in consideration of both the first target vehicle Cp1 and the second target vehicle Cp2.

Fig. 10 is a flowchart explaining a case where the CACC system 300 determines a preceding vehicle and a further preceding vehicle using the sensor of the own vehicle according to an embodiment of the present disclosure.

The CACC system 300 may first determine the driving lane W using the front image (S210). Specifically, the CACC system 300 may acquire a front image including lane information using a camera through the information collection unit 310, and may determine the driving lane W by extracting a lane through image processing.

If the driving lane W is determined, the CACC system 300 may determine a front vehicle traveling in the driving lane W using the sensing result of the distance sensor 311 (S220). For this, the CACC system 300 may determine an object having a width equal to or greater than a predetermined first reference width among the objects in the driving lane W sensed by the distance sensor 311 as the preceding vehicle Cp1.

Next, the CACC system 300 may determine a further forward vehicle Cp2 traveling in the driving lane W using the determined position of the forward vehicle Cp1. For this reason, the CACC system 300 may acquire the second reference width corresponding to the position of the front vehicle Cp1. After the second reference width is acquired, the CACC system 300 may determine an object having a width equal to or greater than the second reference width among the objects in the driving lane W sensed by the distance sensor 311 as the more preceding vehicle Cp2.

The CACC system 300 may determine the first target vehicle and the second target vehicle by comparing the preceding vehicle Cp1 and the further preceding vehicle Cp2 determined as described above with the information of the nearby vehicles acquired through the communication unit 320 (S300).

Hereinafter, the method for controlling the CACC system 300 will be described in detail in the case where the driving lane W is a straight line and a curved line, respectively.

Fig. 11 is a flowchart illustrating a case where the CACC system 300 determines a preceding vehicle and a further preceding vehicle using a sensor of the own vehicle on a straight traveling lane according to an embodiment of the present disclosure.

Referring to fig. 11, the cacc system 300 may determine a driving lane W using a front image (S210). Specifically, the CACC system 300 may acquire a front image including lane information using a camera, and may determine the driving lane W by extracting a lane through image processing.

If the driving lane W is determined, the CACC system 300 may determine the front vehicle Cp1 traveling in the driving lane W using the sensing result of the distance sensor 311 (S220). For this, the CACC system 300 may determine an object having a width equal to or greater than a predetermined first reference width among the objects in the driving lane W sensed by the distance sensor 311 as the preceding vehicle Cp1.

The CACC system 300 may determine a minimum reference width (i.e., a second reference width) that can be determined as a more forward vehicle Cp2 using the position of the forward vehicle Cp1 (S231). As described above with reference to fig. 7, the CACC system 300 may confirm the positions P1, P2, and P3 considering the position of the distance sensor 311 as an origin, and may confirm the second reference width according to equation 1.

If the second reference width is confirmed, the CACC system 300 may confirm an object having a width equal to or greater than the reference width among the objects sensed by the distance sensor 311 (S232). Further, the CACC system 300 may confirm whether the confirmed object for the reference time has a width equal to or greater than a second reference width (S233).

If the confirmed object does not have a width equal to or greater than the second reference width for the reference time, the CACC system 300 does not determine the confirmed object as a more forward vehicle to perform the end operation.

In contrast, if the confirmed object for the reference time has a width equal to or greater than the second reference width, the CACC system 300 may determine the confirmed object as the more-ahead vehicle Cp2 (S234).

Fig. 12 is a flowchart illustrating a case where the CACC system 300 determines a preceding vehicle and a further preceding vehicle using the sensor of the own vehicle on a curved travel lane according to an embodiment of the present disclosure.

Referring to fig. 12, the cacc system 300 may determine a driving lane W using a front image (S210). Specifically, the CACC system 300 may acquire a front image including lane information using a camera, and may determine the driving lane W by extracting a lane through image processing.

If the driving lane W is determined, the CACC system 300 may determine the front vehicle Cp1 traveling in the driving lane W using the sensing result of the distance sensor 311 (S220). For this, the CACC system 300 may determine an object having a width equal to or greater than a predetermined first reference width among objects in the driving lane W sensed by the distance sensor 311 as the preceding vehicle Cp1.

The CACC system 300 may determine a minimum reference width (i.e., a second reference width) that can be determined as a further front vehicle Cp2 using the determined position of the front vehicle Cp1 (S231). As described above with reference to fig. 7, the CACC system 300 may confirm the positions P1, P2, and P3 considering the position of the distance sensor 311 as an origin, and may confirm the second reference width according to equation 1.

If the second reference width is confirmed, the CACC system 300 may confirm an object having a width equal to or greater than the reference width among the objects sensed by the distance sensor 311 (S232). Further, the CACC system 300 may confirm whether the distance sensor 311 senses a plurality of surfaces of the confirmed object (S235).

If surfaces of the confirmed object are not sensed, the CACC system 300 does not determine the confirmed object as a more forward vehicle to perform an end operation.

Conversely, if multiple surfaces of the confirmed object are sensed, the CACC system 300 may determine the confirmed object as the further front vehicle Cp2 (S234).

As described above, the CACC system proposed according to the present disclosure controls the speed in consideration of not only the first target vehicle but also the second target vehicle that is the target vehicle of the first target vehicle, and thus can provide a safe driving environment to the driver.

On the other hand, it should be understood that CACC is illustrated in the specification for ease of explanation. The CACC is only one of the various ADAS functions and the CACC implementation proposed according to the present invention may also be used to implement other related ADAS functions. For example, the proposed method according to the invention can even be used to implement one or a combination of ADAS functions such as CACC, ACC (adaptive cruise control), LCDAS (lane change decision assistance system), LDWS (lane departure warning system), LKAS (lane keeping assistance system), RBDPS (road boundary departure prevention system), PDCMS (pedestrian detection and collision mitigation system), CSWS (curve speed warning system), FVCWS (vehicle ahead collision warning system) and LSF (low speed following).

In one or more exemplary embodiments, the functions explained may be implemented by hardware, software, firmware, or some combination thereof. Where implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both communication media and computer storage media including certain media that facilitate transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of non-limiting example, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or another magnetic storage device, or another medium that can be accessed by a computer and used to transfer or store desired program code in the form of instructions or data structures. Also, a connection may be properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or another remote source using a coaxial cable, fiber optic cable, twisted pair, digital Subscriber Line (DSL), or wireless technologies (e.g., infrared, radio, or ultra-high frequency), then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies (e.g., infrared, radio, or ultra-high frequency) are included in the definition of medium. Disk and disc, as used herein, includes Compact Disc (CD), laser disc, optical disc, digital Versatile Disc (DVD), floppy disk and blu-ray disc. Generally, a disk magnetically reproduces data, and a disc optically reproduces data by a laser. Combinations of the above should also be included within the scope of computer-readable media.

Where embodiments are implemented by program code or code segments, it should be appreciated that the code segments may refer to processes, functions, subroutines, programs, routines, subroutines, modules, software packages, classes, or instructions, data structures, or some combination of program commands. A code segment may be coupled to another code segment or a hardware circuit by transmission and/or reception of information, data, arguments, parameters, or memory contents. Information, arguments, parameters, and data may be passed, forwarded, or transmitted using some suitable means including memory sharing, message transmission, token transmission, and network transmission. Additionally, in some aspects, the steps and/or operations of a method or algorithm may reside as one, combination, or set of codes and/or commands on a machine readable medium and/or computer readable medium, which may be integrated as a computer program composition.

In the case of software implementation, the above-described techniques may be implemented by a module (e.g., a procedure or a function) that performs the above-described functions. The software codes may be stored in memory modules and executed by processors. The memory unit may be implemented within the processor or external to the processor, and in this case, the memory unit may be communicatively coupled to the processor via various means as is known in the art.

In the case of a hardware implementation, the processing unit may be implemented in at least one of an Application Specific Integrated Circuit (ASIC), a Digital Signal Processor (DSP), a Digital Signal Processing Device (DSPD), a Programmable Logic Device (PLD), a Field Programmable Gate Array (FPGA), a processor, a controller, a microcontroller, a microprocessor, other electronic units designed to perform the above-described functions, and a combination thereof.

As described above, one or more embodiments are illustrated. Not all possible combinations of components or methodologies are described for purposes of illustrating the above embodiments, but one of ordinary skill in the art will recognize that many additional combinations and permutations of various embodiments are possible. Accordingly, the above-described embodiments are intended to embrace all such alternatives, modifications and variances which fall within the true meaning and scope of the appended claims. Furthermore, the terms "comprises" and/or "comprising," as used in the specification and claims, means that one or more other components, steps, operations, and/or devices are not excluded from being present or added in addition to the described components, steps, operations, and/or devices.

As used herein, the term "estimate" or "evaluation" refers to a process for determining or estimating a system, environment, and/or user state from a set of observations typically dominated by events and/or data. The estimate may be used to identify a particular situation or operation and may produce, for example, a probability distribution over states. The estimation may be probabilistic and the computation of a probability distribution over corresponding states may be based on a consideration of data or events. Estimation may be a technique for constructing upper layer events from a set of events and/or data. Such an estimation may estimate new events or actions based on a set of observed events and/or stored event data, whether the events are correlated in close temporal proximity, and whether the events and data come from one or multiple event and data sources.

Furthermore, the terms "component," "module," or "system" used in the description of the present disclosure are not limited thereto, but may include hardware, firmware, a combination of hardware and software, or computer-related examples, such as software in execution. For example, a component is not limited in its name, but may be a process executing on a processor, an object, an executable thread of execution, a program, and/or a computer. For example, the operating device and the application driven on the operating device may all be components. One or more components can reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate with each other by local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from a local system, another component of a distributed system, and/or some component interacting with other systems via the signal over a network such as the internet).

It should be understood that the above-described embodiments are exemplary to facilitate easy understanding of the present disclosure, and do not limit the scope of the present disclosure. Therefore, the scope of the present disclosure is defined by the appended claims, and it is to be construed that all corrections and modifications derived from the meaning and scope of the appended claims and equivalent concepts fall within the scope of the present disclosure.

Claims

1. A cooperative adaptive cruise control CACC system provided in a host vehicle to control a running speed of the host vehicle, comprising:

a communication unit configured to: receiving vehicle information including location and travel information from a nearby vehicle using V2V, vehicle-to-vehicle communication;

an information collection unit configured to: collecting vehicle information of a neighboring vehicle and vehicle information of a host vehicle using a sensor provided on the host vehicle; and

a control unit configured to:

determining a leading vehicle and a further leading vehicle using the sensor disposed on the host vehicle;

selecting a first target vehicle followed by the host vehicle and a second target vehicle followed by the first target vehicle, based on vehicle information of the host vehicle and a further host vehicle and vehicle information of the nearby vehicle acquired by the communication unit; and

controlling the traveling speed of the own vehicle based on the speed information of the selected first and second target vehicles,

wherein the control unit is configured to select the first target vehicle by:

selecting vehicles traveling in the same lane as the host vehicle as a first set of vehicles of potential interest;

selecting vehicles present within a predetermined distance from the first set of vehicles of potential interest as a second set of vehicles of potential interest, wherein the distance is measured by the V2V communication and sensors disposed on the host vehicle;

selecting vehicles from the second set of vehicles of potential interest that have a difference between the speed information received through the V2V communication and the speed measured through the sensor within a predetermined value as a third set of vehicles of potential interest; and

selecting one vehicle of the third set of vehicles of potential interest as the first target vehicle to be followed by the vehicle.

2. The CACC system according to claim 1, wherein the control unit comprises:

a state management unit configured to: managing a state of the CACC system;

a target vehicle selection unit configured to: determining a preceding vehicle and a further preceding vehicle using the sensor provided on the own vehicle, and selecting a first target vehicle followed by the own vehicle and a second target vehicle followed by the first target vehicle, based on vehicle information of the preceding vehicle and the further preceding vehicle and vehicle information of the nearby vehicle acquired by the communication unit; and

a travel management unit configured to: the travel speed of the own vehicle is controlled based on the speed information of the selected first and second target vehicles.

3. The CACC system according to claim 2, wherein the state management unit displays the state of the CACC system as one of:

an off state in which the CACC system is not operating;

a standby state in which the CACC system operates but does not control the traveling speed of the own vehicle;

an ACC active state in which the traveling speed of the own vehicle is controlled using only information acquired from the own vehicle in a state in which there is no vehicle connected by V2V communication in the region of interest; and

a cooperative activation state in which there are nearby vehicles connected by V2V communication in the region of interest, and the traveling speed of the own vehicle is controlled using information from the nearby vehicles acquired by the V2V communication and information acquired from the own vehicle.

4. The CACC system of claim 2, wherein the information collection unit comprises a distance sensor configured to sense a forward object,

wherein the target vehicle selection unit determines presence of a preceding vehicle and a further preceding vehicle traveling in the same lane as the lane of the own vehicle, based on a sensing result of the distance sensor.

5. The CACC system according to claim 4, wherein the target vehicle selection unit determines an object having a width equal to or larger than a first predetermined reference width in a driving lane of the own vehicle as a preceding vehicle, and determines an object having a width equal to or larger than a second reference width in the driving lane of the own vehicle, which is acquired by a position of the preceding vehicle, as a further preceding vehicle, according to a sensing result of the distance sensor.

6. The CACC system according to claim 5, wherein if a curvature of a traveling lane of the own vehicle is smaller than a predetermined reference curvature, the target vehicle selection unit determines an object having a width equal to or larger than the second reference width during a predetermined reference time as a more preceding vehicle, and

wherein the target vehicle selection unit determines an object, which the distance sensor senses the plurality of surfaces and has a width equal to or greater than the second reference width, as a more preceding vehicle if the curvature of the driving lane is equal to or greater than a predetermined reference curvature.

7. The CACC system according to claim 5, wherein the target vehicle selection unit obtains the second reference width based on a distance to a preceding object and a position of a preceding vehicle.

8. The CACC system according to claim 2, wherein the travel management unit controls the own vehicle to travel according to any one of a first travel speed corresponding to the travel information of the first target vehicle and a second travel speed corresponding to the travel information of the second target vehicle.

9. The CACC system according to claim 8, wherein the running management unit controls the own vehicle to run according to one of the first running speed and the second running speed having a smaller value.

10. The CACC system according to claim 4, wherein the travel management unit controls the own vehicle to travel at a travel speed determined from the travel information of the first target vehicle and the second target vehicle when the first target vehicle deviates from the travel lane of the own vehicle in a case where the curvature of the travel lane of the own vehicle is smaller than a predetermined first reference curvature.

11. The CACC system according to claim 10, wherein the travel management unit determines whether the first target vehicle deviates from the traveling lane of the host vehicle using the speed and position of the first target vehicle obtained from the sensing result of the distance sensor.

12. A method for controlling speed in a coordinated adaptive cruise control CACC system provided in a host vehicle to control the traveling speed of the host vehicle, comprising the steps of:

acquiring, by a communication unit, vehicle information of a nearby vehicle using V2V communication;

determining, by a controller, a leading vehicle and a further leading vehicle using a sensor disposed on a host vehicle;

determining, by the controller, a first target vehicle and a second target vehicle by comparing vehicle information of the own vehicle with vehicle information of a preceding vehicle and a further preceding vehicle;

determining, by the controller, a travel speed of the host vehicle using travel information of the first target vehicle and the second target vehicle; and

controlling the own vehicle by the controller according to the determined running speed,

wherein selecting the first target vehicle comprises:

selecting vehicles traveling in the same lane as the host vehicle as a first set of potentially interesting vehicles;

selecting vehicles existing within a predetermined distance from the first set of vehicles of potential interest as a second set of vehicles of potential interest, wherein the distance is measured by the V2V communication and sensors disposed on the own vehicle;

selecting one vehicle in the third set of vehicles of potential interest as the first target vehicle to be followed by the vehicle.

13. The method of claim 12, wherein the step of using the sensors of the host vehicle to determine the leading vehicle and the further leading vehicles comprises:

sensing a front object;

determining a preceding vehicle that is traveling in the same lane as the traveling lane of the own vehicle based on the sensing result; and

determining a further forward vehicle using the determined position of the forward vehicle.

14. The method of claim 13, wherein the step of determining a leading vehicle comprises: according to the sensing result, an object having a width equal to or greater than a predetermined first reference width in a driving lane of the own vehicle is determined as a preceding vehicle, and

wherein the step of determining a further forward vehicle comprises: according to the sensing result, an object having a width equal to or larger than a second reference width, which is acquired by the position of the preceding vehicle, in the driving lane of the own vehicle is determined as the further preceding vehicle.

15. The method of claim 14, wherein the step of determining a further forward vehicle comprises: determining an object having a width equal to or greater than the second reference width during a predetermined reference time as a more preceding vehicle if the curvature of the driving lane is less than a predetermined reference curvature, and

wherein the step of determining a further forward vehicle comprises: determining an object, which senses the plurality of surfaces and has a width equal to or greater than the second reference width, as a more forward vehicle if the curvature of the driving lane is equal to or greater than a predetermined reference curvature.

16. The method of claim 14, wherein the step of determining a further forward vehicle comprises:

acquiring the second reference width based on the distance to the front object and the position of the front vehicle; and

an object in the driving lane of the own vehicle having a width equal to or larger than the acquired second reference width is determined as a more preceding vehicle.

17. The method according to claim 13, wherein the step of determining the travel speed of the own vehicle using the travel information of the first target vehicle and the second target vehicle includes:

acquiring a first driving speed corresponding to driving information of a first target vehicle;

acquiring a second driving speed corresponding to the driving information of a second target vehicle; and

the travel speed of the host vehicle is determined from either one of the first travel speed and the second travel speed.

18. The method according to claim 17, wherein the step of determining the travel speed of the own vehicle from any one of the first travel speed and the second travel speed includes:

determining one of the first running speed and the second running speed having a smaller value as a running speed of the own vehicle.

19. The method according to claim 13, wherein the step of determining the travel speed of the own vehicle using the travel information of the first target vehicle and the second target vehicle includes:

determining whether the first target vehicle deviates from the traveling lane of the host vehicle if the curvature of the traveling lane of the host vehicle is smaller than a predetermined first reference curvature; and

if it is determined that the first target vehicle deviates from the traveling lane of the host vehicle, the traveling speed of the host vehicle is determined using the traveling information of the first target vehicle and the second target vehicle.

20. The method of claim 19, wherein determining whether the first target vehicle deviates from a driving lane of the host vehicle comprises:

using the speed and position of the first target vehicle, it is determined whether the first target vehicle deviates from the driving lane of the host vehicle.